Film developing apparatus



July 3, 1962 M. E. FULTON FILM DEVELOPING APPARATUS 2 Sheets-Sheet 1 Filed NOV. 24, 1958 MEAVM/ F Joli.

INVEN TOR. 2/ lrropusg July 3, 1962 M. E. FULTON 3,

FILM DEVELOPING APPARATUS Filed Nov. 24, 1958 2 Sheets-Sheet 2 MEQV/A/ 11751. 7mg,

INVENTOR. 6

United States Patent Filed Nov. 24, 1958, Ser. No. 775,801 21 Claims. (Cl. 95-94) This invention relates to improved apparatus for developing motion picture film and other strip type film by advancing it successively through a series of treating fluids.

A major object of the invention is to provide film developing apparatus of this type which is extremely compact as compared with prior similar apparatus, and yet is capable of handling very large quantities of film at a high rate of production. To attain this compactness, a device embodying the invention is designed to utilize extremely small volumes of the different treating fluids, while at the same time controlling the path of film travel in a manner effectively assuring proper contact of the film with the fluids. The fluids may be contained within passages of very small cross-section, through which the film is advanced longitudinally. In this connection, certain particular features of the invention have to do with the unique formation of the apparatus to facilitate rapid initial threading of the film into the apparatus, in spite of the small size of the fluid passages. Further, the apparatus is specially designed to guide the film through these small passages without any danger of ever contacting the film except along its edges.

Structurally, a unit embodying the invention includes a plurality of tanks for containing different fluids through which the film is to be advanced. Into each of these tanks there projects a guide structure, which is relatively withdrawable from the associated tank, and which forms with the tank the discussed narrow film passages. The film in advancing through one of the tanks passes first along one side of the guide structure and then in a reverse direction along the other side of the guide structure. The latter preferably carries at its inner end a roller about which the film passes in reversing its direction of travel. In order to initially thread the film into the apparatus, it is necessary merely to relatively move the guide structures out of the tanks, to make the entire film directing apparatus completely accessible for threading.

The side surfaces of the guide structures, and the opposed walls of the fluid tanks, are desirably given a unique concave configuration which permits only the edges of the film to engage these surfaces under any circumstances. Also, the various guide rollers may have their film engaging surfaces of a similar concave configuration. These concave guide surf-aces may be of a width such that they can effectively handle films of several different sizes in a single device, and all without engaging more than the extreme edge portions of any size of film.

The above and other features and objects of the present invention will be better understood from the following detailed description of the typical embodiments illustrated in the accompanying drawings in which:

FIG. 1 is a side view, partially broken away, of a film developing device constructed in accordance with the invention;

FIG. 2 is an enlarged section taken on line 2-2 of FIG. 1;

FIG. 3 is an enlarged fragmentary vertical section taken on line 3--3 of FIG. 1;

FIG. 4 is an enlarged fragmentary perspective view of one of the film guide units of the device;

FIG. 5 is a view representing one of the rollers about which the film passes;

FIG. 6 is a view similar to FIG. 5, but showing a variational shape of roller; and

3,041,953 Patented July 3, 1962 FIGS. 7 through 11 are horizontal sectional representations of several additional forms of fluid chamber and guide structure which may be employed.

Referring first to FIG. 1, I have shown at 10 a type of film developing apparatus constructed in accordance with the invention, and which functions to perform the entire series of developing, fixing, washing, and drying operations required for complete developing of a strip of film represented at 11. This film may be a motion picture film, of any conventional size, or may be a strip, or series of interconnected strips, of film from a still camera. In passing through the apparatus 10, the film 11 advances successively through a series of vertically extending parallel tanks 12, which contain the proper fluids for treatment of the film. The film is held and guided by a guide assembly represented generally at 13, which assembly is adapted to be raised vertically by a power operated hoist or other means diagrammatically represented at 14, to a position in which the film and its gniiding parts are completely out of the tanks 12 and are therefore accessible for very rapid and easy threading of the film onto the guide rollers.

The tanks 12 of the first form of the invention are of straight cylindrical vertically extending configuration, with the vertical axes 15 of the different tanks preferably all being aligned within a common vertical plane. The lower ends of the tanks 12 are all closed, as by a common horizontal bottom wall 16 which may be stationarily mounted to a suitable base structure represented at 17. The upper ends of these various cylindrical tanks 12 are open, preferably terminating upwardly in an upper circular edge 18 lying in a horizontal plane. All of these upper edges 18 of the different tanks 12 preferably lie in the same horizontal plane. To receive fluid which overflows from tanks 12 past upper edges 18, there is provided an overflow tray 19, having a bottom wall 20 which extends horizontally at a level beneath upper edges 18 of the different tanks, and which is imperforate except at the locations of tanks 12. At those points, the various tanks extend upwardly through circular openings 21 in bottom wall 20 of the tray, and are welded or otherwise secured thereto in fluid tight relation. The peripheral edge portion of the tray is turned upwardly at 22, around the entire periphery of the tray, to prevent escape of any fluids from within tray except through a predetermined drain line 23 connected into bottom wall 20 and leading to a sewer or other discharge location.

From the lower end of each of the tanks 12 (except for the final dryer tanks or chambers 12'), there extends a fluid discharge line 25, leading to a pump 26 which maintains a continuous flow of fluid through tank 12. This fluid is continually replenished, at a very slow rate, by fluid slowly dripped into the tank, or otherwise slowly fed thereinto, as through a small feed line represented at 27.

The film holding and guiding structure 12 includes an upper horizontally elongated rigid carrier part or member 28, to which there are rigidly attached a series of downwardly projecting parallel guide parts 29 which are received within tanks 12in the FIG. 1 active condition of the apparatus. Member 28 also carries a series of film guide rollers 30, which are rotatable about individual horizontal parallel axes 31 relative to member 28. These axes 31 desirably lie in a common horizontal plane 132, as is seen clearly in FIG. 1. One of the rollers 31 is provided between each pair of adjacent tanks 12, while another roller is provided in advance of the first of these tanks, and still another is provided beyond the final tank. In advancing through the apparatus, the film first passes about the upper side of the initial roller 30', the film then passes downwardly in the first tank at one side of the part 29 located therein, and then advances upwardly at the opposite side of part 29 for engagement with the second of the rollers 30, following which the film then passes through the other tanks 12 in succession in the same manner described in connection with the first tank.

Each of the parts 29 carries at its lower end an additional roller 32, with all of these rollers 32 being mounted to their respective parts 29 for rotation about individual horizontal parallel axes 33 lying in a common horizontal plane 34. These axes 33 extend parallel to axes 31 of the upper rollers 30. As will 'be apparent, when the film. 11 reaches the lower end of one of the parts 29, the film passes about the underside of the associated lower roller 32, before advancing upwardly at the opposite side of part 29.

After passing about the upper side of the final upper roller 30", film 11 is wound onto a takeup reel 35. Roller 30 is driven at a constant speed by a motor represented schematically at 36. Motor 36 may also drive takeup reel 35 through a suitable slipping belt or clutch arrangement well known to the motion picture industry, and may in some instances also drive others of the rollers 30 (say every third roller) to assist in advancement of the film. Reel 35 may be mounted on a projection 37 attached to carrier part 32. Roller 30 may have a cylindrical, instead of concave, film engaging surface, which may be covered with a soft material such as rubber or felt to prevent the possibility of scratching the film. The film is held tightly against roller 30" by another roller 38, rotatably mounted to an arm 39 which is pivoted at 40 to carrier part 28. A spring typically acts to urge arm 39 and the carried roller 38' downwardly against the film 11, to prevent slippage of film 11 over roller 30", and thereby assure effective driving of the film by the roller. Motor 36 and reel 35 may be mounted on projection 37 or on any other convenient portion of the machine.

With reference now to FIG. 2, it is noted that each of the parts 29 located within one of the chambers or tanks 12 is of a uniform cross-section along its entire vertical extent, that cross-section being 'the same as is shown-in FIG. 2. This part 29 acts as a partition member, functioning to form along its opposite sides two vertically extending parallel fluid filled spaces or passages 42 and 43, through which the film 11 passes first downwardly and then upwardly as it advances through the tank 12. To define the inner sides of these passages 42 and 43, part 29 has two vertically extending opposite side walls, which are in horizontal section of the concave configuration represented in FIG. 2. More particularly, these walls 44 preferably curve arcuately in horizontal sections with a curvature which may be the same as the curvature of the cylindrical wall of tank 12. These two side walls 44 of part 29 may be joined together at their opposite ends by two arcuate walls 45, which curve along the inner surface of, and substantially engage, the wall of tank 12. At its upper and lower ends, the hollow part 29 is closed by two horizontal top and bottom walls 46 and 47.

Internally, part 21 is divided into four internal vertically extending passages 48, 49, t) and '51, which are separated from one another by two mutually perpendicular imperforate partitions 52 and 53. Fluid from the previously mentioned pump 26 may be fed into one or more of these passages, say the passages 48 and 49 of FIG. 2, to then flow outwardly from those passages through perforations 54 formed in walls 44, to thereby be directed against the inner emulsion side of film 11. In flowing from pump 26, the fluid may pass through a flexible line represented at 55, which connects into a fitting 56 threaded into and rigidly attached to carrier part 28. This fitting 56 is also threadedly attached to or otherwise rigidly secured to the member 29, to in this way secure member 29 in fixed position relative to carrier 28. Fitting 56 may connect into member 29' in 4 a manner such as to communicate equally with both of the chambers 48 and 49 within part 29.

The fluid which is circulated downwardly through passages 48 and 49 and then through apertures 54 against the film is one of the film treating or washing fluids. This fluid preferably at all times substantially fills the two spaces 42 and 43 within which the film is received in each tank 12. In order to maintain the film treating fluid at an optimum predetermined temperature, I provide means for circulating a temperature control fluid, preferably water, within the other two passages 50 and 51 in member 29. More particularly, a pump 57 (see diagrammatic representation in FIG. 1) may draw water at a predetermined temperature from a heated thermostatically regulated supply tank 158, with the pump discharging through a line 58 leading into passage 50 in member 29. The fluid passes downwardly within this passage, and may then cross into passage 51 at the lower end of member 29', to flow upwardly within passage 51 and discharge, through a line 59 leading back to tank 158. The cross-flow of temperature control fluid between chambers 50 and 51 may be permitted by terminating the partition 52 therebetween at a point 66 (FIG. 3) which is spaced, a short distance above the bottom horizontal imperforate wall 47 of member 29. The lines leading to and from circulation passages 50 and 51 are of course flexible to allow for upward and downward movement of the film holding assembly. Also, passages 50' and 51 are of course completely isolated from passages 48 and 49, so that the temperature control fluid does not contact or mix with the film treating fluid.

The lower rollers 32 may be mounted to their respective members 29 by means of an essentially U-shaped mounting bracket 61 rigidly attached to and projecting downwardly beyond bottom wall 47 of member 29. Each of the rollers 30' and 32 desirably has an outer film. engaging annular surface which, in axial cross-section, has an arcuate configuration very similar to the arcuate curvature of concave sidewalls 44 of member 29. These concave surface rollers are preferably so positioned as to direct the film 11 downwardly and upwardly within spaces 42 and 43 at locations which are centered therein, so that the film does not under normal conditions engage the sidewall of tank 12 or sidewalls 44 of part 29. The relationship of the parts for attaining this purpose is represented in FIG. 2, in which it is clear that the annular concave surfaces 63 of rollers 32 preferably projects somewhat beyond positions of true vertical alignment with the walls 44.

The purpose of the concave configuration of all of the surfaces which normally, or under any circumstances, guide or direct the film 11 is to avoid contact of any of these guiding parts with more than the very edge portions of the film being handled. This is brought out very clearly in FIGS. 2 and 5, in which it is obvious that the film 11 can only engage the concave arcuate surfaces 62 and 63 of the rollers at the very edges '65 of the film. This is true also of the arcuate surfaces of tank '12 and walls 44, which form guide passages 42 and 43, and which surfaces cannot possibly engage more than edges 65 of the film if the film slacks for any reason, or under other circumstances is brought into contact with the mentioned surfaces. It is also noted particularly that the arcuate concave curvature of the roller surfaces, and the surfaces of parts 12 and 29 which form passages 42 and 43, allows the apparatus to be utilized for handling any of various different widths of film, since any size of film can be passed about the concave rollers and through the concave walled passages without danger of contacting more than the edge of the film with the guiding surfaces. This is indicated in FIG. 5, in which several different sizes of film are shown positioned in contact with the illustrated roller. This unique feature of the invention is considered to be a feature of very considerable importance from a practical standpoint, since it is extremely important that the apparatus be designed to handle film with a minimum possibility of damage to the image bearing portion of the film.

Each of the parts 29 which projects downwardly into one of the tanks 12 may carry a rigid guide loop 66 near its lower end, through which the film passes just before reaching the lower roller 32. This loop may be attached at its opposite ends to the two opposite side portions of U-shaped bracket member 61, with the loop 66 curving in essentially a horizontal plane and at a location spaced inwardly a short distance from the inner surface of tank wall 12. As is brought out clearly in FIG. 2, the film passes downwardly within this guide loop 66, and then advances into contact with the concave outer guide surface of lower roller 32, to pass thereabout. The loop 66 thus effectively holds the film against movement off of roller 32.

While I have described specifically the various fluid circulation passages, pumps, etc., of only one of the tanks 12 and its associated member 29, it will be obvious that similar pump and piping circuits, as well as internal passages, are provided for each of the other tanks 12 and its contents. In some cases, certain tanks which may be serving the same function, for example, where several developer tanks or several fixing bath tanks are employed, the fluid circulation systems of these tanks may be connected in series, to use a common pump. For simplicity of description, however, we may assume that in the arrangement being described, each of the tanks 12 (except for the film drying tank or tanks) has associated therewith an entirely separate circulation system of the type described in connection with the left hand tank in FIG. 1.

Where ablack and white type of film is being developed, and a system of maximum simplicity is being employed, there may be provided only five of the tanks 12. The first four of these tanks would contain respectively a developer fluid, washing water, a fixing bath, and a second washing water bath. The fifth tank, or perhaps a series of final tanks, could serve the function of drying the film. These dryer tanks or chambers are provided with air blowing and heating units 67, typically at their lower ends as shown in FIG. 1, functioning to blow heated air upwardly through the tanks or passages 12' to dry the film before it reaches the final take-up reel 35. Where color film is being developed, there may be provided a greater number of the tanks 12 (typically 13 tanks), for performing all of the numerous operations which must be carried out in developing such film. Also, if both black and white and color film are to be developed in a common device, all of the various black and white and color solutions may be provided, and the film may then merely be threaded past any of the tanks which are to be skipped in a particular developing operation.

To describe now the manner of use of the apparatus shown in FIGS. 1 through 5, the first step may be to actuate hoist 14 in a manner to elevate the film holding and guiding assembly 13, including carrier part 28, rollers as, parts 29, and rollers 32. These parts are elevated high enough to move the lowermost rollers 32 completely out of tanks 12, so that they are readily accessible for easy threading of a leader portion of film 11 onto the various rollers. This film 11 is passed about the first upper roller 30', then passed downwardly along one side of the first member 29, and through its associated guide loop 66, following which the film is passed about the lower roller 32 associated with that member 29, and is then advanced upwardly along the opposite side of the member 29 for passage about another of the upper rollers 30. This threading operation is continued until the film has been threaded about all of the various rollers 30 and 32, to the condition represented in FIG. 1. The unit 13 is then lowered by hoist 14 in a manner advancing the various parts 29 and rollers 32 downwardly to their FIG. 1 positions within tanks 12. Next, the various pumps 26 may be placed in operation to start the circulation of developer fluid, fixing liquid, washing water, etc. through the different tanks 12. More particularly, each of these fluids flows from its pump 26 through line 55 into the interior of part 29, to flow downwardly through passages 48 and 49, then outwardly through apertures 54 into the film containing spaces 42 and 43. This fluid is continuously re circulated in the manner previously described, except in the case of washing water where the discharge line connected to the bottom of the tank (for example line 25' in FIG. 1) may discharge directly into a waste outlet, rather than recirculating the washing water. At the same time, the temperature control water is continuously recirculated within passages 50 and 51, in the manner previously described, to maintain the entire interior of each of the tanks 1.2 at a predetermined optimum temperature. If the temperatures to be maintained in all of the tanks 12 under a particular set of circumstances are the-same, then the same pump 57 and tank 158 can be utilized for passing temperature control fluid through all of the different members 29. Further, it will be obvious that in the drying chambers 12', there is of course no circulation of any treating liquid in contact with the film.

After the fluids have all been placed in circulation, motor 36 may be started, to actuate roller 30 and reel 35 to commence the advancement of the film through the various tanks. As the film'advances through these tanks, the film is first developed, then washed, then fixed, then washed, then dried, or any other set of predetermined operations are performed, to ultimately produce the completely developed film on the reel 35.

All of the various parts of the apparatus whichcontact any of the developer fluids or water are of course formed of a material which is capable of withstanding contact with the particular fluid engaged, without damage. For this purpose, I find it desirable to form the parts 29, rollers 30 and 32, and the roller mounting parts, of a resinous plastic material, such as polyvinyl chloride. For maxi-mum facility of formation, the part 29 may be extruded to the illustrated cross-sectional configuration, with top and bottom walls 46 and 47 being applied to the extrusion after its formation. Also, perforations 54 may be formed in the part after extrusion thereof.

FIGS. 6 and 7 represent portions of a somewhat variational form of the invention, in which all of the film guiding rollers may have film engaging concave surfaces 62a which appear as straight lines in cross-section, rather than as arcuate lines. More particularly, the outer concave annular surface 62 of each roller is defined by two frustro-conical surfaces 162a, which taper toward one another and to a point 163 of minimum diameter. As is brought out in FIG. 6, this frustro-conical type of concave roller surface also functions to assure that only the very edge portions of the film 11a can engage surfaces 62a of the rollers. Similarly, in FIG. 7, the part 29a may have its film engaging and guiding surfaces or Walls 44a shaped in essential conformance with the crosssectional configuration of the roller of FIG. 6. That is, this wall 44a may have two portions 144a which advance inwardly away from the wall of tank 12a as they advance toward one another. Here again, only the very edge portions of the film can engage the walls 44a. FIG. 8 shows an arrangement which is very similar to that of FIGS. 1 to 5, except that the opposite side Walls 44b of part 29b merge together at their central points 14411, so that the film passing spaces 42b and 43b are somewhat larger, and so that the interior of part 2% is automatically divided into two isolated passages 48b and 50b within which any desired fluids may be circulated. The fluid passing into passage 48!) may be a film treating fluid, which emits through apertures 54b into contact with the film.

FIG. 9 shows still another arrangement, in which the outer wall of each tank is of square cross-section, but has two vertically extending insets 70 connected to its opposite sides, with the central guide structure or member 7 290 having the cross-sectional configuration shown in FIG. 9. Here again the parts 290 and the tank wall elements 70 are so shaped as to give the surfaces 71 which might be engaged by a film an arcuate curving configuration very similar to that of FIGS. 1 to 5.

FIG. 10 shows an arrangement in which the inner removable guide structure 29d includes two arcuate wall members 44d similar to walls 44 of FIGS. 1 to 5, but interconnected by a vertically extending pipe 171 which may be utilized for transmission of a treating fluid, with that fluid passing through apertures 54d into the film passing spaces 42d and 4301. Another closely similar arrangement is shown in FIG. 11, in which two fluid conducting vertical lines or passages 72 and 73 are provided, for passing fluid through apertures 54a against the film. It will of course be understood that, in each of the variational forms shown in FIGS. 6 through 11, the basic over all arrangement of the tanks and the vertically movable film guide assembly may be essentially the same as in FIGS. 1 to 5.

I claim:

1. Apparatus for developing a strip of film comprising a plurality of generally vertically extending tanks for containing film treating fluids through which said film is to be passed, and means for guiding said film strip through said tanks successively, said guiding means including a plurality of generally vertically extending guide structures receivable in said tanks respectively, and a plurality of guide rollers rotatably carried by said guide structures respectively near the lower ends thereof, said means in guiding the film through the individual tanks being constructed to direct the film first downwardly into the tank along one side of one of said guide structures and then about the underside of the roller carried thereby and upwardly along the opposite side of the guide structure toward the top of the tank, said guide structures and tanks being relatively vertically movable to withdraw the guide structures from the tanks, and the individual guide structures having surfaces at their opposite sides adapted to engage said film and which in cross section are concave and form essentially vertically extending grooves progressively deepening toward their centers so that a film will engage said surfaces only along essentially two single lines of contact at the opposite edges of the film.

2. Apparatus as recited in claim 1, in which said guide rollers have concave film engaging surfaces progressively deepening toward their centers to assure engagement of the rollers with the film only along essentially two single lines of contact at the opposite edges of the film.

3. Apparatus as recited in claim 1, in which said tanks have inner surfaces opposite said concave side surfaces of the guide structures and adapted to engage said film, said inner surfaces formed by the tank being concave in cross section and forming essentially vertically extending grooves progressively deepening toward their centers and in a direction away from the guide structures so that a film will engage said tank surfaces only along essentially two single lines of contact at the opposite edges of the film.

4. Apparatus as recited in claim 1, in which said tanks are of essentially circular cross section, and said guide structures extend substantially entirely thereacross, said concave side surfaces of the individual guide structures having an essentially arcuate cross sectional configuration of a curvature approximately the same as the walls of said tanks within which they are received.

5. Apparatus as recited in claim 1, in which said rollers have concave film engaging surfaces which progressively deepen toward their centers to engage a film essentially along only two lines of contact at the opposite edges of the film, said roller surfaces being of continuously curving concave cross sectional configuration in a plane extending transversely of the engaged film.

6. Apparatus as recited in claim 1, in which said film guiding means include guide loops carried by and project but above the locations of said rollers and through which the film is passed to be laterally confined thereby.

7. Apparatus as recited in claim 1, in which at least one of said guide structures is hollow and contains a fiuid circulation passage through which a fluid is circulated through the interior of the guide structure and then outwardly from the guide structure to its exterior and into contact with the film in the associated tank.

8. Apparatus as recited in claim 1, including means for circulating a temperature control fluid within the interior of at least one of said guide structures in isolation from the film treating fluid in said tank to control the temperature thereof.

9. Apparatus as recited in claim 1, including means attaching said guide structures together, said guide structures being withdrawable simultaneously and as a unit from said tanks.

10. Apparatus for developing a strip of film comprising a plurality of generally vertically extending tanks for containing film treating fluids through which said film is to be passed, means for guiding said film strip through said tanks successively, said guiding means including a plurality of generally vertically extending guide structures receivable in said tanks respectively, and a plurality of guide rollers rotatably carried by said guide structures respectively near the lower ends thereof, said means in guiding the film through the individual tanks being con structed to direct the film first downwardly into the tank along one side of one of said guide structures and then about the underside of the roller carried thereby and upwardly along the opposite side of the guide structure toward the top of the tank, said guide structures and tanks being relatively vertically movable to withdrawthe guide structures from the tanks, and means for circulating a temperature control fluid within the interior of at least one of said guide structures in isolation from the film treating fluid in said tank to control the temperature thereof.

11. Apparatus for developing a strip of film comprismg a plurality of generally vertically extending tanks for containing film treating fluids through which said film is to be passed, means for guiding said film strip through said tanks successively, said guiding means including a plurality of generally vertically extending guide structures receivable in said tanks respectively, and a plurality of guide rollers rotatably carried by said guide structures respectively near the lower ends thereof, said means in guiding the film through the individual tanks being constructed to direct the film first downwardly into the tank along one side of one of said guide structures and then about the underside of the roller carried thereby and upwardly along the opposite side of the guide structure to ward the top of the tank, said guide structures and tanks being relatively vertically movable to withdraw the guide structures from the tanks, at least one of said guide structures having a first fluid passage therein communicating with the space at the outside of said structure but within the associated tank, and also a second fluid passage therein isolated from the first passage and from the space at the exterior of the structure, means for circulating a first fluid through said first passage and outwardly therefrom into contact with said film, and means for circulating a temperature controlling second fluid through said second passage to control the temperature of the first fluid without contacting it.

12. Apparatus as recited in claim 1, in which said guiding means include additional rollers near the upper ends of said guide structures about which said film passes in advancing into and out of the tanks.

13. Apparatus as recited in claim 1, including a carrier part attached to and carrying said guide structures and adapted to be withdrawn therewith from said tanks,

said guiding means including rollers mounted to said carrier part and about which said film passes in travelling to and from said tanks.

14. Apparatus for developing a strip of film comprising a plurality of vertically extending generally parallel tanks for containing different film treating fluids through which said film is to be passed, a film guide assembly which is vertically movable relative to said tanks and which includes a series of downwardly projecting guide structures adapted to project into said tanks respectively and withdrawable upwardly therefrom by upward movement of said assembly, said assembly including first rollers carried thereby near the upper ends of said guide structures and additional rollers carried at the lower ends of said structures, said first rollers and said additional rollers being positioned to guide the film along a path extending first downwardly within one tank at one side of said guide structure therein, then about one of said additional rollers, then upwardly along the opposite side of said structure and upwardly from said tank, and then successively along similar paths through the other tanks, said guide structures and said tanks having opposed surfaces for confining and guiding said film therebetween.

as it moves along said opposite sides of a guide structure, said opposed surfaces of the guide structure and tank being of oppositely concave cross-section and progressively advancing away from one another toward their transverse central areas so that a film will engage said surfaces only along essentially two single lines of contact at the opposite edges of the film, said first rollers and said additional rollers having concave film engaging surfaces which progressively deepen toward their centers to engage a film along its opposite edges.

15. Apparatus as recited in claim 14, including means for circulating some of said fluids through the interiors of said guide structures and then outwardly through apertures therein to contact said film, and means for circulating a temperature controlling fluid in said guide structures in isolation from the film treating fluids therein to control the temperature thereof.

16. Apparatus for developing a strip of film comprising a plurality of tanks for containing film treating fluids through which said film is to be passed and means for guiding said film strip through said tanks successively, said guiding means including a plurality of guide structures receivable in said tanks respectively, and a plurality of guide rollers rotatably carried by said guide structures respectively at inner ends thereof, said means in guiding the film through the individual tanks being constructed to direct the film first into the tank along one side of one of said guide structures and then about the roller carried thereby and back along the opposite side of the guide structure, and guide loops carried by and projecting laterally from said guide structures respectively at locations in advance of the locations of said rollers respectively and through which the film is passed before extending about the rollers to be laterally confined by the loops for proper engagement with the rollers, said loops having concave inner film engaging surfaces for engaging the film at only the opposite edges thereof.

17. Apparatus as recited in claim 16, in which said loops are essentially arcuate.

18. Apparatus as recited in claim 16, in which each of said rollers has a film engaging surface, said film engaging surface of each roller and of the loop which is located in advance thereof being of a configuration to curve concavely essentially away from one another to each engage only the edges of said film.

19. Apparatus as recited in claim 1, including guide loops carried by and projecting laterally from said guide structures at locations near but above the locations of said rollers respectively and through which the film is passed to be laterally confined thereby, each of said rollers and the loop which is near it having film engaging surfaces which curve concavely and arcuately essentially away from one another to each engage only the edges of said film.

20. Apparatus for developing a strip of film comprising a plurality of generally vertically extending tanks for containing film treating fluids through which said film is to be passed, means for guiding said film strip through said tanks successively, said guiding means including a plurality of generally vertically extending guide structures receivable in said tanks respectively, at least one of said guide structures having a hollow vertically extending portion, and a plurality of guide rollers rotatably carried by said guide structures respectively near the lower ends thereof, said means in guiding the film through the individual tanks being constructed to direct the film first downwardly into the tank along one side of said hollow vertically extending portion of said one guide structure and then about the underside of the roller carried by that guide structure and upwardly along the opposite side of said hollow portion thereof toward the top of the tank, said guide structures and tanks being relatively vertically movable to withdraw the guide structures from the tanks, said hollow portion of said one guide structure contaim ing a fluid circulation passage through which a fluid is circulated through the interior of said hollow portion and then outwardly in opposite directions therefrom to its exterior and into contact with the film at opposite sides of said hollow portion.

21. Apparatus as recited in claim 20, including pump means for circulating said fluid along an endless path extending first through said hollow portion of said one guide structure, then from said hollow portion in opposite directions into the tank and then from said tank and back to said hollow portion for recirculation.

References Cited in the file of this patent UNITED STATES PATENTS (1st Addition of 990,898) 

